Valve for internal combustion engines



y 11, G. w. DOUGLAS ET AL 2,165,238

' VALVE FOR INTERNAL COMBUSTION ENGINES Filed March 21, 1936 ml NVENTORS fiwrge iif'flaug/as info/m hie 1i: law q Patented July 11, 1939 UNITED STATES PATENT OFFICE VALVE FOR. INTERNAL COMBUSTION I ENGINES Application March 21, 1936, Serial No. 10,122

4 Claims.

This invention relates in general to valve construction and more particularly to poppet valves for use in internal combustion engines and is an improvement on the construction disclosed in 5 U. S. Letters Patent to George W. Douglas and John J. Dewey for Valve for internal combustion engines, No. 2,019,255, dated October 29, 1935.

It is essential in the operation of an internal combustion engine, that the valves function and seat properly. Such valves, as'the poppet type, arranged in the cylinder head are subjected to extreme conditions brought about in the combustion chamber tending toward deterioration of the valve and malfunctioning thereof. These deteriorations take the form of carbon deposits, warping, pits, and unevenness of wear of the valve by its contact with its seat. The results are leaky valves or sticking valves. As long as the valve is pitted or has unevenly distributed carbon deposits, leaking of the valves and loss of compression will result. As long as the valve stem is burdened with unevenly distributed carbon deposits sticking valveswill result.-

Heretofore it has been the common accepted practice to provide a poppet valve with a unitary stem against which a cam actuated tappet bears to open the valve. A spring is provided to return the valve to its seat subject to the operation of the tappet. The movement of the valve is purely reciprocatory. Now, particularly in connection with the exhaust valve, one side of the valve seat, as well as one side of the valve and stem, are being constantly subjected to more extreme heat and resulting carbon deposits.

It is therefore an object of this invention to provide a valve and an improved means of operating the valve so that in addition to a reciprocatory movement the valve is also slightly rotated during each cycle of operation so that 4 the wear and the carbon deposits and extreme heat will, by reason of the rotation of the valves, be evenly distributed on the valve and its stem. In this manner the valve head will not burn on one side as different parts of the valve are con- 45 stantly being seated on different parts of the valve seat. This will also tend to eliminate carbon deposits on the valve seat as-the movement of the valve will tend to pulverize the carbon.

Another object of the invention is to provide 50 such a valve assembly that will efiectively conduct the heat absorbed from the cylinder head to its operating tappet without 10%.

Another object is to provide such a valve assembly that will be so simple and inexpensive in 55 nature that the conventional valve assemblies with the principles of the invention.

It is also an object of the invention to provide an improved valve assembly wherein the valve spring will be relieved of the usual sudden shock a when the valve drops into its seat in order to prevent broken valve springs.

In the usual design of poppet valve construc-, tion in internal combustion engines it is necessary to remove the spring in order to grind or re- 10 move-the valves. This entails a laborious operation and a checking of the spring when it is replaced to determine its proper functioning when the valve and its spring are again assembled for operation. 16

In order to avoid these diiiiculties, another further object of the invention is to provide a valve, stem valve spring and spring retainer, and means of mounting of the same whereby it will notbe I necessary to remove the spring when removing 20 the valve and further where it is merely necessary to apply the proper tool to the valve head and grind the same against its seat without removing the valve or spring or disturbing the relationship therebetween. 25

In the aforementioned patent, the valve stem is made up of two parts, the upper part which carries the valve head and the lower part of which is rotatable with the upper part but locked against relative rectilinear movement. The lower part is 30 actuated by the tappet and carries a spring retainer to be engaged by the valve spring to urge the valve against its seat. This arrangement provides for a slight rotation of the valve as it is reciprocated during each valve operation. It also 36 permits grinding of the valve without disassembling the valve spring. This construction, however, does call for a substantial modification of the conventional valve stem, as it is made up of two parts. 40

In the present invention it is proposed to obtain the beneficial results of valve rotation during reciprocation and grinding without disturbingthe spring merely by providing the usual single unit valve stem with an abutment near its'extremity and a single unitary spring retainer engaging the abutment and so connected to the stem as to be readily removable and replaceable on the valve stem and also slidable and rotatable thereon and normally spring pressed against the abutment so as to have its outer surface extend past the outer extremity of the valve stem. The action of the tappet is to push the sp i%gg retainer against the action of the springrelieves the valve from spring pressure as the coil spring is compressed and, in turn, the natural twisting of the coil spring imparts a slight rotary movement to the spring retainer. The spring retainer fits snugly but rotatably and reciprocably about .the valve stem and during the-valve-opening operation, when the valve is relieved of the spring frictionally from the spring retainer to the valve stem and hence to the valve. Furthermore, it is a simple matter to jack up the retainer out of its extended position so that the valve-may rotate in grinding without disturbing the spring or causing any torsion thereof.

The objects and nature of our inventionwill become more apparent upon a further-reading of the following specification and appended claims, certain embodiments of the invention being shown in the accompanying drawing, in which:

Figure 1 is a fragmentary view in vertical section taken through a cylinder head showing the piston and valve in the combustion chamber.

Figure 2 is a view in elevation of the valve and stem, showing the spring retainer in vertical section and at its lowermost position and the tappet abutting the spring retainer and out of contact with the valve stem.

Figure 3 is a view in section taken along line 3-3 of Figure 2, without the spring, showing a form of spring retainer and its means of removable attachment to the valve stem.

Figure 4 is a view similar to Figure 2 showing the tappet abutting both the valve stem and the spring retainer.

Figure 5 is a view in elevation of the valve and stem, showing in vertical section a modified formv of tappet, the tappet being out of contact with the spring retainer and a resiliently urged member of the tappet in contact with the valve stem.

Referring more particularly to the drawing, the cylinder l and its head 2 are shown with the usual type of combustion chamber 3. The cylinder is shown as provided with the usual type of piston I having a connecting rod 5 connected to the piston 4 by means of a wrist pin 6. The

cylinder may be water-jacketed, as shown as I,

that portion of the jacket I adjacent the valve stem guide 8 being slightly enlarged at 9 while the other side of the valve stem guide is waterjacketed, as shown at it). The usual spark plug II is also shown as projecting into the combustion chamber.

For purposes of description the valve shown at I2 is referred to as an exhaust valve, inasmuch as it is the exhaust valve that is subjected to the relatively more strenuous heat conditions. It must be remembered, however, that the improvement constituting our invention is equally applicable to intake valves and therefore our invention consists in improvements as applied to intake as well as exhaust valves.

Referring to Figure 2 the valve head I! may be provided with the usualrecesses l3 to receive a suitable tool for grinding operations against the valve seat; The valve head is shown provided with a stem portion H which is enlarged and bevelled to provide an abutment at I at its lower or outer extremity.

The preferred form of spring retainer I6 is shown in Figure 3 as having a reduced section I! so as to receive the lower, or outer, end of the comprelion coil spring IS, the other end of which engine driven tappet 2| is merely contacting the retainer, the retainer snugly, but rotatably, engages the enlarged portion or abutment I! of the valve stem. The lower on outer surface of the spring retainer is so fitted that it may extend past the lower, or outer extremity of the valve.

stem for a predetermined distance. Upon a further upward movementof the tappet, the retainer is lifted upwardly from the enlarged portion or abutment I5 and the valve is, relieved of the downward pressure of spring ID. The retainer is thus forced upwardly by the tappet comparatively independently of the valve stem until the tappet reaches the position shown in Figure 4 where is contacts the lower, or outer, end of the valve stem. Further upward movement of the tappet moves the retainer and valve, simultaneously, but independently, during the valve opening operation brought about by the tappet.

Upon the completion of the return movement necessary for the closing of the valve, the spring retainer, under the action of the spring, travels a predetermined distance-against the enlarged portion or abutment I5 to assume the position shown in Figure 2, where the lower surface of the retainer extends past the lower extremity of the stem. In Figure 5 there is shown a modified form of tappet22 which is hollow and provided with a relatively light compression coil spring 23 bearing on the partition 24 to urge the collar 25 and pin 26 thereon upwardly against the lower extremity of the valve stem. Spring 23 is extremely light in comparison to spring l8 and merely acts as a shock absorbing means for the relative movement of the stem and retainer to minimize vibration and noise inoperation of the engine;

Due to the torsion of spring l8 during its compression and expansion under the influence of the tappet, a slight rotative force is transmitted to the retainer. This rotative force is transmitted from the retainer to the valve stem during the time that the retainer is urged by the spring against the enlarged portion or abutment l5, so that the stem and retainer turn as a unit. This valve rotation takes place during valve-closing operations, for during valve-opening operations the retainer is not urged against the stem abutment so that relative movement between the retainer and the valvestem results as the spring twists.

' In assembling the valve in the internal combustion engines it is merely necessary to push the valve stem downwardly through the valve stem guide 8. The compression coil spring I8 may then be placed around the valve stem guide Due .to the flow of the exhaust gases in the combustion chamber, that portion of the cylinder shown at 30 is being subjected to relatively more extreme heat than the remaining sides of the cylinder. The valve head has been generally referred to at I2 and the valve seat has also been generally indicated at 26 but it will be seen that if the valve head remained in this fixed position,

' other than its reciprocatory movement. that portion of the valve head indicated at 12 would be subjected to relatively greater temperatures and carbon deposits than would the remainder of the valve head by reason of the fact that this portion l2 would be the only portion of the valve head that would be contacting with that portion of the valve seat indicated at 26 and further would always be in the position directly opposing the flow of hot exhaust gases. It follows that the valve stem, if it did not rotate, would also be subiected on its side facing the direction of flow of the exhaust gases to a relatively greater extreme heat and carbon deposits than would the remainder of the valve stem.

With the arrangement of the present invention, the valve and stem are rotated step-by-step in the same direction during the successive valve closing operations, so that the extreme heat conditions to which the valve and stem are subjected is evenly distributed throughout all sides thereof. This minimizes and tends to eliminate warping of the valve head and the formation of carbon deposits and pits in the valve head, valve stem or seat. The carbon which would otherwise be deposited on the valve seat will be pulverized by reason of the possible rotary movement of the valve as it returns to its seat under the urging of the compression spring.

It will be readily seen that when it is desired to grind valves it is merely necessary to engage the head portion with a suitable tool and rotate the same after the camshaft has been rotated in such a position that the valve head rests approximately against its seat, leaving, otcourse, sufficient clearance to receive the valve grinding component. Inasmuch as the valve head and the stem is rotatable with relation to the retainer, such a rotation in the grinding operation may be freely performed without consideration of the compression spring iii. In other words, the grinding operation, as distinguished from the conventional practice, does not entail the removal of the valve spring. In practice it may be desirable to jack up the spring retainer to permit free and easy rotation of the valve and valve stem.

Further this arrangement tends toward the elimination of broken valve springs inasmuch as the valve head is free to rotate as it seats and comes into contact with the seat before the extreme lower point of movement of the valve stem and thus the spring is not subjected to the usual sudden stop when the valve engages its seat. Furthermore the tappet may turn freely as there is no binding in the valve head inasmuch as there is no positive twisting connection between the spring and the valve stem or valve head, or in other words because the valve head and valve stem are rotatable with respect to the spring. Because of the direct abutting connection between the tappet 2i and the end of the valve stem H, any turning of the tappet is also imparted to the valve 12.

As previously stated the wear on the valve stem by reason of the cam action on the lifting operation will be evenly distributed insofar as the valve stem is concerned and consequently there will be less tendency towards valve stem guide leakage.

Furthermore by reason of the slippage provided for in the valve stem, the valve will not chatter as it seats, especially when the tappet arrangement of Figure 5 is employed, which also has the advantage that the additional twist of the spring 23 is imparted to the valve l2 in the interval that the valve stem I4 is released from retainer 11.

We claim:

1. In combination with avalve and valve stem, spring means for normally seating said valve, operating means for unseating said valve against the action of said spring, a member carried by said stem and secured thereto adjacent one extremity of said stem so as to be reciprocable and rotatable thereon for retaining said spring under compression, said member being capable of movement on said stem so that its outer surface may extend past said extremity of said stem, said operating means being provided with a ri id element for directly engaging said retaining member and a resiliently urged element for directly en-. gaging said valve stem.

2. In combination in an internal combustion engine, a valve and a valve seat, a valve stem and a guide therefor, a. spring and retaining means aging the same for urging said valve against its seat, said retaining means consisting of a unitary member secured to and carried by said stem near one extremity thereof, said retaining member being rotatable with respect to said stem and reciprocable thereon so that the outer surface of said retaining member may extend past said extremity of said stem, engine driven means for initially engaging the outer surface of said retaining member to urge the latter inwardly against the action oi said spring and independently of said valve, consequently releasing said valve from the action oi said spring and subsequently jointly moving said valve and retaining member upon further movement of said engine driven means to unseat said valve, said engine driven means being provided with a rigid element, for directly engaging said retaining member and a resiliently urged element for directly engaging said valve stem.

3. In combination in an internal combustion engine, a valve and a valve seat,a valve stem and a guide therefor, a compression spring and retaining means releasably engaging the same for urging said valve against its seat, said retaining means consistingof a unitary member removably secured to andcarried by said stem near one extremity thereof for maintaining said spring under compression between said member and said valve stem guide, said retaining member being rotatable with respect to said stem and reciprocable thereon so that the outer surface of said retaining member may extend past said extremity of said stem, engine driven means for initially engaging the outer surface of said retaining member to urge the latter inwardly against the action of said spring and independently of said valve, consequently releasing said valve from the action of said spring and subsequently jointly moving said valve and retaining member upon further movement of said engine driven means to unseat said valve, said engine driven means provided with a rigid element for directly engaging said retaining member and a resiliently urged element for directly engaging said valve stem.

4. In combination in an internal combustion engine, a reciprocatory poppet valve, valve stem and a valve seat, spring means for seating said valve, engine driven means for unseating said 10 Based directly by said engine driven means iniamazes tially to move said member and reciprocate the same independently of said stem, said stem being subsequently engaged by and reciprocated by said engine driven means, said engine driven means being provided with a rigid element for directly engaging said retaining member and a resiliently urged element for directly engaging said valve stem.

' GEORGE W. DOUGLAS. JOHN JOSEPH DEWEY. 

